As shown in FIG. 1, mammographic type X-ray systems comprise an X-ray source 10 carried on a bracket 11 disposed at the top of a vertical plate 12. The plate carries an assembly 13 on which a breast 16 under examination is placed, resting on a horizontal shelf 15. A pad 17 which is transparent to X-rays and which is movable vertically along the plate 12 is used to compress the breast 16.
In order to adapt to the size of the patient, the plate 12 is mounted on a vertical column 9 which stands on the ground, and the plate 12 is vertically displaceable along the column by appropriate mechanical means.
Beneath the shelf 15, the top of the assembly 13 includes a tunnel in which a device is housed for receiving a cartridge 18. The cartridge is constituted by a light-proof box housing at least one film 14 which is sensitive to X-rays. A latent image of the breast is formed on this film after an appropriate exposure time, and a picture is obtained by developing the film.
The device containing the cartridge, referred to as the "cartridge support", is a removable item which is slid into the tunnel before exposure and into which the cartridge is inserted. X-ray-sensitive films come in standard sizes, e.g. 18 cm.times.24 cm or 24 cm.times.30 cm, and the same applies to the cartridges which are designed to contain them and to the cartridge supports.
In order to switch from a cartridge of a given size to another of a different size, it is normally necessary to change the cartridge support at the same time. A cartridge support is generally provided for each size of cartridge, thereby constituting a kind of adaptor which is associated with each type of cartridge. This gives rise to additional expense when it is desired to use a given mammograph with all of the normal sizes of cartridge, and it also required that bulky items, such as the cartridge support, are handled during examination. An object of the present invention is therefore to provide a device for installing cartridges, which device is capable of adapting to the various sizes of the cartridge that are used in this application. Such devices already exist, and one such device is described in U.S. patent application Ser. No. 07/497709 filed Mar. 23, 1990, now U.S. Pat. No. 4,989,227.
This prior art device suffers from the drawback of being complicated and therefore of being relatively expensive. Another object of the present invention is therefore to provide a device for installing mammography cartridges which is simple in design and cheap.